Hello Everyone! Let me start off by saying this forum has been a tremendous help! I just registered but I have used this forum to help me replace the transmission and shift selector cable. Thank you everyone for your contributions!!

I have a 95 GMC Jimmy 4.3L SLT 4x4.

I've noticed there is a gas leak only when the engine is running. No leaks when not running or when I turn the key to the on position. I do see gas dripping down from under the truck when running and after crawling underneath I found 2 heavy drips. One appears to be dripping down from the torque converter cover and another dripping from the transmission cooler lines.

Can you guys give me some tips on how I should proceed?

Side note:
The transmission replacement went well (all things considered...) but I was unable to place the nut and spring on one bolt on each side of the Y pipe where it connects to the engine. There are no threads on the bolt. 2 out of 3 of the bolts on the Y pipe are secure but there's a slight exhaust leak. I don't think gas is leaking from the Y pipe where it attaches to engine.

 

I think your leak could be from the return fuel line. Moving everything around during the trans work could have done it. Sound like it could be above the tranny which is not going to be an easy fix.

 

Hi newguy and thank you for the quick reply. How would I go about checking the fuel line? Would the return fuel line only leak when the engine is running?

 

definately coming from rusted out metal lines which cros over the top of the transmission.

I rerouted my lines so I dont have to deal with that hassel should I have any problems with my fuel lines and replaced then.
My lines run from the back of the engine across over to the frame and down the length of it like how it should have been done from the factory.
the 2cnd gens are nice looking vehicle but for working on them the engeneers design everything to be difficult to work on.

 

Hi 1sttimejimmy owner, thanks for the quick reply. I've had the trans replaced several times on this truck and one thing we noticed was the fuel lines were not really running on or by the trans, they were more up by the side of the frame. How difficult of a job is it to replace the lines myself or should I have a mechanic do that?

 

Its not realy that hard of Job it should be something you can do.1st figure out what line it is thats leaking.If its one of the ones that are screwed in to the back of the planem unscrew it.you should check the whole length of the line for rust.More than likely it is.Cut it off at a good spot and get a length of replacement line.Also get some compression fittings for the same size diamter.splice your new piece of line onto where you cut off the old line at.There should be some threads on here or on google and look youtube videos for replacing the fuel line.Depending on how mych mechanical experience you have it shouldnt take more than half hour tops.
Another thing while your underneith the the truck replace you fuel filter if it hasnt been done.That will be a little more trickier than the 1st Job.

 

the return line has very little pressure. you could replace the whole lengrh with rubber fuel line. Would be the cheapest route also

 

Those metal fuel lines dont cost that much.To dissagree respectfully rubber line is about the same price as metal.I can get 5 ft section of 3/8 metal line for about $6 and some change.7/16 line is about the same price.The replacement metal lines will last the rest of the lifetime of your vehicle unless you you rupture it by hitting something.IMO rubber line is good when you need to connect metal line in short pieces.I have also found at least in my area for rubber fuel line it cost about $1 per foot.Also just to give you an idea on how much mechanic would charge you if the hourly rates of the shops in my area are the same as yours your looking at about $50-$60

 

Update: The truck doesn't leak gas when running idle. I need to apply throttle for it to start leaking. Once leaking, there are several heavy drips coming down from around the torque converter shield area.

 

I`d rather have metal also but me just thinks rubber is way easier